XS500 Issues. Help?

[cegan09]

Hi, New here and in search of help. I have a 1976 XS500 that i've been tinkering with for a while trying to get everything set right.

My latest issues come in the form of timing and carb sync. First timing.

I set timing, dead on, went for a ride, checked again and it was way advanced. I reset and couldn't get it right. The plate is adjusted fully to one side, and can't go any further. I've been told this requires resetting the gap to hopefully center everything again. Sound accurate? Right now the timing mark sits on the red line of this picture.

Now i just want to check, on the plate there is the "T" mark, then 2 lines, then "FR" then two lines, then a space, then V. For normal tick over timing it should be at the two lines to the right of FR, then at rev it should be at V. Am i correct on this?




Carb sync. I know i don't have fuel set right, and i think i'm lean at idle, however i wanted to set sync semi-close to right before i mess with them again. I made a sync gauge with the tried and true oil in long clear tube technique. At full closed throttle the left cylinder pulls way more vacuum. As soon as you open the throttle just a little but (say rev to 2100) the right pulls way more. What could be causing this? Diaphragms are brand new, carbs were professionally cleaned within the last year and 500 miles, valve clearances were set within 1000 miles (though i'm going to check them again).

Please feel free to school me on anything i'm doing wrong, i'm in this project to learn.

[JimR]

Originally Posted by cegan09

Hi, New here and in search of help. I have a 1976 XS500 that i've been tinkering with for a while trying to get everything set right.

My latest issues come in the form of timing and carb sync. First timing.

I set timing, dead on, went for a ride, checked again and it was way advanced. I reset and couldn't get it right. The plate is adjusted fully to one side, and can't go any further. I've been told this requires resetting the gap to hopefully center everything again. Sound accurate? Right now the timing mark sits on the red line of this picture.

Now i just want to check, on the plate there is the "T" mark, then 2 lines, then "FR" then two lines, then a space, then V. For normal tick over timing it should be at the two lines to the right of FR, then at rev it should be at V. Am i correct on this?




Carb sync. I know i don't have fuel set right, and i think i'm lean at idle, however i wanted to set sync semi-close to right before i mess with them again. I made a sync gauge with the tried and true oil in long clear tube technique. At full closed throttle the left cylinder pulls way more vacuum. As soon as you open the throttle just a little but (say rev to 2100) the right pulls way more. What could be causing this? Diaphragms are brand new, carbs were professionally cleaned within the last year and 500 miles, valve clearances were set within 1000 miles (though i'm going to check them again).

Please feel free to school me on anything i'm doing wrong, i'm in this project to learn.

FR is good for the right cylinder FL for the left and the v mark for the advance !!!
you could do with a set of vacuum gauges to balance the carbs with should be done at 1000 rpm & you use the screw set between the carbs to get the readings the same..

[cegan09]

Originally Posted by JimR

FR is good for the right cylinder FL for the left and the v mark for the advance !!!
you could do with a set of vacuum gauges to balance the carbs with should be done at 1000 rpm & you use the screw set between the carbs to get the readings the same..

I know FR is for right and FL is for left, i just used the FR picture because it's the best one i have. I'm still unsure on what marks are the correct ones. The FR and FL are so close to the lines on either side of it that it could be either one. The shop manual says that at tick over it should be at the lines to the left of FR (or FL), but other people have said it should be the ones to the right. This is why i'm confused.

I figured out the other issues. I somehow had the advance mechanism jammed, and it was stuck open. solved and now it freely moves back to normal.

I have made a sync/balance gauge. I also had that wrong. I had one side so far open it was screwing everything up. Reset by eye, fixed with the gauge, and now it's dead on. Bike starts with one kick when cold, something it's never done for me before.

[JimR]

Originally Posted by cegan09

I know FR is for right and FL is for left, i just used the FR picture because it's the best one i have. I'm still unsure on what marks are the correct ones. The FR and FL are so close to the lines on either side of it that it could be either one. The shop manual says that at tick over it should be at the lines to the left of FR (or FL), but other people have said it should be the ones to the right. This is why i'm confused.

I figured out the other issues. I somehow had the advance mechanism jammed, and it was stuck open. solved and now it freely moves back to normal.

I have made a sync/balance gauge. I also had that wrong. I had one side so far open it was screwing everything up. Reset by eye, fixed with the gauge, and now it's dead on. Bike starts with one kick when cold, something it's never done for me before.

That's Good !!! to be fair the dwell angle being set would help the idle & start up, but I cannot find a single cylinder dwell meter on the market ... don't forget carb driven motor cycle engines are classed as singles EG a twin is 2 singles and a four is 4 singles ... so all electronic tools need to be for single cylinder and then just used on the next cylinder